A new study has attempted to determine whether Wyeth Pharmaceuticals’ controversial antidepressant Effexor (generic: venlafaxine) has the potential to cause birth defects in babies born to mothers who take the drug during their first trimester of pregnancy. The research involved data from the National Birth Defects Prevention Study (NBDPS), and found ‘statistically significant associations’ between Effexor exposure and a number of serious congenital abnormalities. The results of the study suggest that, when taken by expecting mothers early on in the course of their pregnancies, Effexor can cause severe birth defects.

What’s the problem?

The study, which was conducted by a research team led by Kara N. D. Polen, involved mothers with pregnancies affected by one of 30 selected birth defects, and a control group of babies born without congenital abnormalities with estimated dates of delivery between 1997 and 2007. Exposure was defined as any maternal use of Effexor from one month preconception through the third month of pregnancy. The results of the study found that, among the 27,045 NBDPS participants, 0.17% (14/8002) of control mothers and 0.40% (77/19,043) of case mothers reported any use of Effexor during the designated exposure periods.

The research identified ‘statistically significant associations’ between Effexor exposure and the following congenital birth defects:

Manufactured and marketed by Wyeth Pharmaceuticals, Effexor is an antidepressant that belongs to a controversial class of medications known as serotonin-norepinephrine reuptake inhibitors (SNRIs). Drugs from this class are typically prescribed to treat depression and generalized anxiety disorders. Studies have estimated that approximately 20% of pregnant women suffer from depression, and nearly 10% suffer from anxiety. Taking these figures into consideration, it is easy to understand why millions of pregnant women around the country are prescribed Effexor and other similar antidepressants each and every year.

Yet despite its widespread popularity and considerable effectiveness as an antidepressant medication, Effexor has once again proven to be dangerous to unborn babies when taken by expecting mothers early on in the course of their pregnancies. Polen’s research team concluded that there are indeed strong correlations between periconceptional use of Effexor and the above-listed birth defects. However, the authors caution that the study’s sample size was quite small, and that additional research needs to be conducted in the future to confirm the results.